Sectioning means for electric stations.



, E. BRANDENBURG.

SEGTIONING MEANS FOR ELECTRIC STATIONS.

Patented Jan. 27, 1914.

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Witnesses:

E. BRANDENBURG.

SEGTIONING MEANS FOR. ELECTRIC STATIONS.

APPLICATION FILED 00T.2, 1911.

Patented Jan. 27, 1914.

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' Attorney.

uou'mmm' PLANOGRAPH co.. WASHINGTON. n. c,

E. BRANDENBURG.

SEGTIONING MEANS FOR ELECTRIC STATIONS.

APPLICATION FILED 0GT.Z, 1911.

Patented Jan. 27, 1914.

4 SHEETS-TSHEET 3..

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E. BRANDENBURG.

SECTIONING MEANS FOR ELECTRIC STATIONS.

APPLIOATION FILED 0012, 1911.

1,085,375. Patented Jan. 27, 1914.

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Witnesses:

LCILUMDIA PLANDGRAPH CO..WASHINGTON D. c,

EDWIN BRANDENBUR-G, OF BRUSSELS, BELGIUM.

SECTIONING MEANS FOR ELECTRIC STATIONS.

Application filed October 2, 1911.

To all whom it may concern:

Be it known that I, EDWIN BRANDEN- none, a subject of the King ofBelgium, residing at 14 Rue dEstouvelle, Brussels, in the Kingdom ofBelgium, have invented certain new and useful Improvements in SectioningMeans for Electric Stations, of which the following is a specification.

It is known that, in certain central electric stations, in order tolimit the accidental interruptions of the current supply, the parallelrunning of the dynamos is replaced during the hours of heavy load bymultiple unit running. The bus bars are sectioned, and each circuit issupplied by a special dynamo in such a manner that the perturbances incase of accident are limited, and the risk of total stoppage of theworks is eliminated. The excess voltages which occur on opening theinterrupters and cutting out heavy loads, are localized by the previousopening of the sectioning interrupters.

The present invention has for its object to render this system ofsectioning more efiicacious, by making the sectioning interruptersautomatic in their action and more sensitive than the interruptersarranged upon the direct path of the current, so that they may operatemore rapidly, while, at the same time, permitting of efficient runningin parallel. In normal running sectioning only exists virtually, but incase of accident it takes place automatically with certainty andprecision. Furthermore, the device is sufficicntly flexible to permit oflimiting, according to requirements the size of the sections, andconsequently the number of feeders served by a running unit. This pointis essential in order to insure a sufficient service, because in case ofaccident it is important to prevent weakly loaded feeders, from which arunning alternating current generator is not directly branched, frombeing deprived of current by the operation of the sectioninginterrupters.

In the accompanying drawing which is given by way of example, Figure 1shows diagrammatically a general view of a central station equipped inaccordance with the invention. Fig. 2 is a diagrammatic detail view of asection in cases in which triphase current is used. Fig. 3 is adiagrammatic view showing the manner of rendering the reserve dynamooperative in case of accident. Fig. 4 is a diagrammatic view of aSpecification of Letters Patent.

Patented Jan. 27 1914.

Serial No. 652,315.

section in cases in which the safety cut out of the dynamo isautomatically controlled a maximum relay. Fig. 5 shows the automaticcontrol of the safety cut out by a reversing relay and Fig. 6 is asimilar view showing the control of this cut out by the combination of amaximum relay and of a reversing relay.

The bus bars 1 are preferably arranged ring-fashion. Between eachalternator connection a sectioning interrupter 2 is ar ranged. Thefeeders 3 are grouped in numbers proportionate to the power of theunits. Each group may be connected directly with the different sectionsof the ring 1.

The bars of each section are supplied by an alternating currentgenerator 4, provided in the usual manner with a safety interrupter 5.The conductors of the first and of the second phase of the generator 4,are each provided with a primary winding 6 which acts upon a secondarycoil 7 connected with a maximum relay 8. These two relays are sufficientfor protecting the alternator eflicaciously, because an increase ofintensity in the conductor of the third phase makes itself felt in theconductors of one or other of the two other phases. The relays 8 arebranched off a general line 9,,10 in which a battery of cells 12 isprovided to serve for all the sections. In the circuit of this batterythere is interposed a solenoid which acts upon an intermediateinterrupter 13 serving to connect bridge-fashion the circuit of thebattery 12 with the third wire 11 of the general line. The conductors ofthe circuits 14 terminate at the wires 9 and 11 of the general line;solenoids 15 are mounted in these conductors and control the sectioninginterrupters 2. Each of these circuits 14 likewise comprises a lockingcontact 16 actuated by the safety interrupter 5. This may be of theknown oil break type and can be provided with a pin 17 which, upon theoperation of the alternating current generator 4 and consequently theclosing of the interrupter 5, closes the locking contact 16, thusrendering possible the passage of a current through the controllingsolenoid 15. It will therefore be seen that. owing to the contactlocking device, the passage of the current is not possible except in thecircuits 14 which correspond to a running alternating current generatorso that it is possible to vary the size of the section. when, forexample, during the hours of low consumption only a single generator isemployed for supplying the feeders of the several sections.

Assuming that the central station in question comprises four dynamos a b0 (Z as shown in Fig. 1, and that each of the latter operates to supplythe mains, the four corresponding locking contacts will be closed insuch a manner as to permit of the disconnection of all the sectioninginterrupters c g 71 The bus bars will thus be divided into foursections, and in case of accident or trouble of any kind producing anoverload on the dynamos, the disconnection of these interrupters takesplace automatically, in such a manner as to isolate the sections andthus prevent injury to or stoppage of the corresponding dynamos. Thisautomatic disconnection is produced as follows: The maximum relays 8 ofeach over-loaded dynamo act and close the circuit of the battery 12; thesolenoid of the interrupter 13 is energized and attracts its armature insuch a. manner as to inter-pose the battery 12 in the disconnectingcircuit 14. The locking contact 16 being closed the current is able topass through the coil 15 and thus produce the disengagement of thesectioning interrupter 2 in such amanner as to isolate the section ofthe over-loaded generator. It will be seen that when several dynamounits are in. service each of the sections will be defined by theposition of the connection of these units relatively to the bus bars 1.The extent of the sections thus composed diminishes in proportion as thenumber of units in service increases.

If two of the dynamos of the electricity works, for example the dynamosZ) and (Z, are suiiicient for supplying the mains at a given moment, thebus bars will be divided into two sections defined by the sectioninginterrupters la, the disconnecting coils of which are the only onesthrough which the current of the battery 12 is able to pass, the lockingcontact 16 of the other disconnecting coils being open owing to theopening of the safety interrupters 5 of the stopped alternators. Insteadof being operated by hand these intcrrupters 5 may also be controlledautomatically by a maximum relay as seen in Fig. l, sometimes by areversing relay as seen in Fig. 5, but more generally by a reversingrelay'and a maximum relay employed in conjunction as seen in Fig. 6.

As shown in Fig. 4 the safety cutout is, in this case, controlled by asolenoid 18, in the circuit of which maximum relays 19 are interposed,their operation depending upon the intensity of the current passingthrough the conductors connecting the dynamo with the bars 1. isconnected with a source of current of any convenient kind which may bethe same for the entire installation. The battery 12, already rcferredto, may serve this purpose The circuit of the solenoid 18 by addin tothe general line 5), 1O, 11., a fourth conductor 20 to which the secondterminal of the battery 12 is connected. In the case of three phasecurrent two relays 19 are used, but the arrangement of the conductors issuch that the solenoid 18 is energized when one or other of the relayshas acted, as clearly shown in the drawing.

ll hen the solenoid 18 is controlled by a reversing relay 21 the arr:ngement remains the same as shown in Fig. 5, but the contact of therelay, instead of being actuated only by the primary coil 22 which actsupon the secondary winding 23 of the relay, also depends upon a winding2% mounted in shunt on the conductors of the dynamo.

Fig. 6 shows the combination of the maximum relay with reversing rel rys for the control of the cutout These relays are mounted in paralleland the operation of one of them is suliicient for releasing the cutoutIn this case the relays 8 which control the sectioning interruptershould be more sensitive than the relay of the safety interrupter. asotherwise in case of overload the latter would be disconnected morerapidly than the sectioning interrupter 2. and the adjacent sectionsthus remaining connected with the defective section by the bus bars 1would then ha vc to provide the supply for the mains, preriou ly servedby the dynan'io whose safctv interrupter has just opened, and would thusbe over-loaded in their turn, and their successive disconnection andconsequently the total stoppage of the installation would result.

The relays 8 of the sectioning interrupter being more sensitive than themaximum relays of the safety interrupter the latter might really bedispensed with and only reversing relays employed forS21111G,l')0('2\1140 in case of overload the relays 8 act fordisconnecting the sectioning interruptcrs and isolating the over-loadedsection from the adjacent sections. the dynamos of the sec tion underconsideration being then pro tected from any over-load in the latter bythe safety apparatus of the feeders of the section, such oil relays inthe case of alternating current, or fuses in the case of the employmentof continuous current. The arrangement, therefore, permits of retainingfor the direct protection of the alter nators only reversing relays. bytransferring the maximum action to the sole point at which it is neitheran impediment nor a danger, that is to say, upon the path of theexchange currents.

lVhen the safety interrupter 5 of the dynamo is operated automzu icallvthe locking contact 16, instead of depending upon this interrupter, maybe controlled by the interrupter of the excitation circuit of the dynamogenerally operated by hand. This arrangement is represented in 41-, in

which 25 designates the energizing winding of the dynamo 41-, 26designates the regulating rheostat and 27 the excitation switch, theexcitation current being obtained from the battery 12. The lockingdevice 16 is replaced by a third switch key 28 added to the switch 27.This key actuated simultaneously with the switch :27 closes the circuitof the solenoid 15, the corresponding dynamo of which is energized. Thisarrangement is even preferable when the dynamo is protected directly byrapid action reversing relays which act upon the safety interrupter 5and might cause its disconnection before that of the correspondingsectioning interrupter.

In certain cases the locking contact 16 might even be dispensed with andthe maximum relays 8 connected directly without the intermediary ofgeneral line 9, 10, 11. with the disengaging solenoid 15, by employing aseparate battery of cells for each section, these relays being able toact only when the corresponding dynamo is running. This arrangementwhich at first sight would ap pear to be simpler than that previouslydescribed nevertheless presents the defect that if a return should takeplace into one of the running dynamos protected by sensitive reversingrelays the latter in acting directly upon the safety interrupter 5 mightprevent the operation of the relay 8 and consequently of theinterrupters 2, and the object aimed at would not be attained, while thecomplete arrangement, comprising as principal intermediaries a generalline 9, 10, 11 and auxi iary locking contacts 16, insures all thenecessary precision to the sectioning. This defect is, however,eliminated when the re versing relay which controls the interrupter 5 iscaused to act upon the interrupter 2 also.

Fig. 3 shows diagrammatically the very simple means which, with thearrangement in accordance with the invention, permits of rendering areserve dynamo operative in case of accident by the employment ofswitches is Z m n 0 adapted to connect each alternator a 7) c d i withthe right or left hand sections. Thus assuming at the moment in questionthat the dynamos a 0 cl 2' are running, the dynamo 6 being in reserve,and that it is desired to stop the dynamo (Z for example for inspectionor repairs it is only necessary to arrange the switches Z and m in thepositions indicated in broken lines; the switches 7c and 0 may retaintheir initial positions while the switch a is set in the neutralposition.

Although in the preceding description only triphase alternating currentgenerators have been referred to it is obvious that the arrangement isequally applicable to any other type of generator. In the case ofcontinuous current dynamos the relay 8 instead of being controlled bythe current introduced in a secondary coil. 7 is branched directly offthe terminals of a shunt interposed in the circuit of the dynamo.

The intermediary interrupter 13 is not indispensable but is aneconomical auxiliary, because it permits of employing relays of ordinaryconstruction which could not with stand the passage of powerful currentswith out injury. If desired the solenoids controlling the automaticinterrupters might also be replaced by small electric motors, the shaftof which carries a pinion meshing with a small rack which operates thearm of the interrupter.

Obviously without departing from the principle of the invention numerousother modifications might be introduced into the arrangements describedabove which are given by way of example only.

What I claim and desire to secure by Letters Patent of the United Statesis 1. In an electric supply system, in combination with the generators,bus bars conducting current to the feeders, connections between thegenerators and the bus bars, safety interrupters in said connections,sectioning interrupters in said bus bars, solenoids controlling saidsectioning interrupters, a battery common to all the sections, maximumcurrent relays the contacts of which are controlled by the currentpassing through the connections between the generators and the bus barsand are adapted to automatically close the circuit of said battery andactuate said sectioning interrupters to section said bus bars in case ofoverload of a generator.

2. In an electric supply system, in combination with the generators, busbars conducting current to the feeders, connections between thegenerators and the bus bars, safety interrupters in said connections,sectioning interrupters in said bus bars, solenoids controlling saidsectioning interrupters, a battery common to all the sections, meanscontrolled by the current passing in the connections between thegenerators and the bus bars to automatically close the circuit of saidbattery and open the sectioning interrupters in case of overload of agenerator, locking contacts inserted in said battery circuit andoperated by he safety interrupters so that the opening of one of thesectioning interrupters be allowed only when the safety interrupter ofthe corresponding generator is closed.

3. In an electric supply system, in combination with the generators, busbars conducting current to the feeders, connections between thegenerators and the bus bars, safety interrupters in said connections,sectioning interrupters in said bus bars, solenoids controlling saidsectioning interrupters, a battery common to all the sections, a

battery circuit in which said solenoids are inserted, locking keys insaid battery circuit actuated by the interrupter of the exciting circuitof the generator to allow the opening of the corresponding sectioninginterrupter when the interrupter of the exciting circuit is closed,means controlled by the current passing through the connections betweenthe generators and the bus bars to automatically close said batterycircuit and 10 open the sectioning interrupter when the correspondinglocking key is closed.

In testimony whereof I atlix ni signature in presence of two Witnesses.

EDlVIN BRANDENBURG. Witnesses H. T. E. Knutratrnnr, CHAS. ROY NASMITH.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents Washington, I). C.

